OLED Outcoupling Layer with Plasmonic Enhancement for Light Extraction
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Solution Overview
Problem
Existing OLEDs face challenges in efficiently extracting light due to high non-radiative decay rates and limited control over light emission characteristics, particularly in achieving saturated colors and high efficiency.
Innovation Solution
Incorporation of an enhancement layer with plasmonic materials and an outcoupling layer to modify the emission properties, utilizing surface plasmon resonance to enhance light extraction and control emission characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional OLED structures are used, then device simplicity is maintained, but light extraction efficiency is limited due to high non-radiative decay rates
Solution Approach 1:
The patent introduces an enhancement layer containing plasmonic materials as an intermediary component between the organic light-emitting layer and the outcoupling layer. This enhancement layer mediates the light extraction process by utilizing surface plasmon resonance to convert non-radiative decay into radiative emission, thereby improving light extraction efficiency without fundamentally altering the basic OLED structure
Solution Approach 2:
The patent employs composite materials in the enhancement layer by combining plasmonic materials (such as metal nanoparticles or continuous metal films) with dielectric materials. This composite structure enables simultaneous optimization of optical field enhancement and light outcoupling, resolving the contradiction between energy loss and device complexity
2Illumination intensity
If white OLED with absorption filters is used, then color saturation can be achieved, but light extraction efficiency and brightness are reduced
Solution Approach 1:
The patent converts the harmful non-radiative decay (which was previously lost energy) into beneficial radiative emission through surface plasmon resonance in the enhancement layer. By coupling the organic emitter with plasmonic modes, the non-radiative decay channel is transformed into a radiative channel that can be subsequently outcoupled, thereby turning energy loss into useful light emission with improved brightness and color purity
Solution Approach 2:
The patent changes the optical parameters of the OLED system by introducing plasmonic resonance effects that modify the density of optical states and the radiative decay rate. This parameter change enables enhanced light extraction efficiency and improved emission characteristics without requiring absorption filters, thus achieving both brightness and color purity while reducing energy loss
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Improves light extraction efficiency and enables better control over emission spectra, enhancing the performance of OLEDs in terms of brightness and color purity.
Implementation Method 1
Incorporation of an enhancement layer with plasmonic materials and an outcoupling layer to modify the emission properties, utilizing surface plasmon resonance to enhance light extraction
Data Source
AI summary
Emissive devices are provided that include an outcoupling layer having a plurality of nanoparticles such that the outcoupling layer has at least 3 regions possessing distinct bulk refractive index values. One or more dielectric materials are arranged at least partially between the outcoupling layer and an emissive layer of the device.